created docs

samples/c/contours.c

 #include <opencv2/imgproc/imgproc.hpp>
 #include <opencv2/highgui/highgui.hpp>
+#include <stdio.h>
+void help()
+{
+	printf("\nThis program creates an image to demonstrate the use of the \"c\" contour\n"
+			"functions: cvFindContours() and cvApproxPoly() along with the storage\n"
+			"functions cvCreateMemStorage() and cvDrawContours().\n"
+			"It also shows the use of a trackbar to control contour retrieval.\n"
+			"\n"
+			"Call:\n"
+			"./contours\n");
+}
 
 #define w 500
 int levels = 3;
@@ -18,12 +29,14 @@ void on_trackbar(int pos)
     cvReleaseImage( &cnt_img );
 }
 
+
+
 int main( int argc, char** argv )
 {
     int i, j;
     CvMemStorage* storage = cvCreateMemStorage(0);
     IplImage* img = cvCreateImage( cvSize(w,w), 8, 1 );
-
+    help();
     cvZero( img );
 
     for( i=0; i < 6; i++ )